As a result of the Montreal Protocol phasing out ozone depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), industry has been working for the past few decades to find replacement refrigerants. The solution for most refrigerant producers has been the commercialization of hydrofluorocarbon (HFC) refrigerants. The new hydrofluorocarbon refrigerants, HFC-134a being the most widely used at this time, have zero ozone depletion potential and thus are not affected by the current regulatory phase out as a result of the Montreal Protocol. The production of other hydrofluorocarbons for use in applications such as solvents, blowing agents, cleaning agents, aerosol propellants, heat transfer media, dielectrics, fire extinguishants and power cycle working fluids has also been the subject of considerable interest.
There is also considerable interest in developing new refrigerants with reduced global warming potential for the mobile air-conditioning market.
1,1,1,3,3-Pentafluoropropane (CF3CH2CHF2 or HFC-245fa), a refrigerant and blowing agent, may be prepared by fluorination of 1,1,1,3,3-pentachloropropane (CCl3CH2CHCl2 or HCC-240fa) in the liquid phase (see for example, U.S. Pat. No. 6,291,730).
1,1,1,2,2-Pentapropane (CF3CF2CH3 or HFC-245cb), useful as a refrigerant and blowing agent has been prepared by the addition of methyl fluoride to tetrafluoroethylene in the presence of antimony pentafluoride as disclosed in U.S. Pat. No. 6,184,426.
2,3,3,3-Tetrafluoro-1-propene (CF3CF═CH2 or HFC-1234yf), useful as a refrigerant and as a polymer intermediate has been prepared by fluorination of CH3CF2CCl3 over chromium oxide as disclosed by Rausch in U.S. Pat. No. 2,996,555.
1-Chloro-3,3,3-trifluoro-1-propene (CF3CH═CHCl or HCFC-1233zd) is useful as a chemical intermediate and may be prepared by fluorination of HCC-240fa as disclosed in U.S. Pat. No. 6,013,846.
1,3,3,3-Tetrafluoro-1-propene (CF3CH═CHF or HFC-1234ze) useful as a refrigerant has been prepared by dehydrofluorination of HFC-245fa using a strong base in aqueous or alcoholic solution or by means of chromium-containing catalyst in the presence of oxygen at elevated temperature as disclosed in U.S. Pat. No. 6,124,510, and from HCFC-1233zd as disclosed in U.S. Pat. No. 5,895,825. HFC-1234ze has also been prepared from HCC-240fa as disclosed in U.S. Pat. No. 6,111,150.
2-Chloro-3,3,3-trifluoro-1-propene (CF3CCl═CH2 or HCFC-1233xf) is useful as an intermediate and as a monomer for polymers. HCFC-1233xf has been prepared by dehydrochlorination of 1,2-dichloro-3,3,3-trifluoropropane using potassium hydroxide as described by Haszeldine in Journal of the Chemical Society (1951) pages 2495 to 2504.
There is a need for processes for the manufacture of a compound from the group HCFC-1233xf, HFC-245fa, HFC-245cb, HFC-1234ze, HCFC-1233zd, and HFC-1234yf, where other compounds of the group are also produced from common halogenated hydrocarbon starting materials and those other compounds can, if desired, also be recovered.